This issue contains eight contributions on a variety of subjects: usability, real-time and multidatabase systems, air traffic control, intelligent agents, concurrency and group support in objectoriented systems development, and distributed systems.
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Customer requirements play an essential role in product development. Accurate definition and assessment of customer needs and wants form the basis for product offerings. Functional requirements have always been central to product definition, and several methods are available to determine required function. Emphasis on product usability and the end-user interface is continuing to increase as comput...
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In this paper we review the framework for information systems architecture first introduced by Zachman1 and show how it can be applied in the context of real-time systems. Discussions are included throughout the paper to convey some of the characteristics unique to real-time systems and to point out areas of special architectural concern.
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In virtually every organization, data are stored in a variety of ways and managed by different database and file systems. Applications requiring data from multiple sources must recognize and deal with the specifics of each data source and must also perform any necessary data integration. The objective of a multidatabase system is to provide application developers and end users with an integrated v...
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The automation of air traffic control (ATC) applications has challenged the technologies traditionally used for building and testing large data processing systems. These systems are characterized by complex applications, extensive external and user interfaces, and rapidly changing functional requirements. The Advanced Automation System (AAS) of the Federal Aviation Administration combines high ava...
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Episodic classification problems are the transient responsibilities of the knowledge worker—growing and then receding in importance over time. Typically, episodic classification problems do not conform to traditional expert system solutions, and they require specialized architectures to offer decision support and increased span of control for those individuals whose task is expediting the p...
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This paper describes practical design and implementation experiences gained when creating Group Support Systems (GSS) in a networked personal computer environment. Examples of GSS based on the shared context model and implemented using C, C++, and Actor languages are presented. Graphical user interfaces and multitasking extend traditional methods for supporting group work. An object-oriented commu...
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Many attempts have been made to add concurrency to C++, often by extensive compiler extensions, but much of the work has not exploited the power of C++. This paper shows how the object-oriented facilities of C++ are powerful enough to encapsulate concurrency creation and control. We have developed a concurrent C++-based prototype system (ABC++) and describe how we can provide, with a standard comp...
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